I would put the period drama "Amazing Grace" into the category of "admirable, but not necessarily engaging."

William Wilberforce (Ioan Gruffudd, "Fantastic Four") is at a crossroads in his life. Torn between devoting his life to God or the government, his decision is made for him when abolitionist activists (including Rufus Sewell) present William with a chance to expose the slave trade. Instilled with a sense of purpose, William begins the process of implementing change, pitting himself up against Parliament (Michael Gambon, Ciaran Hinds) and the derision of others (Toby Jones) to make his voice heard in a world that wants to maintain slavery for as long as it can last.

Just glance at "Grace" and you can spot the level of class. It has Michael Apted ("Coal Miner's Daughter," the "Up" series of documentaries) directing, Steven Knight ("Dirty Pretty Things") scripting, and a good chunk of top British talent acting; "Grace" has all the components for, at the very least, a quality night out at the movies. The trouble is, that's exactly what you get.

If I sound harsh, that's because "Grace" is perfectly serviceable PBS-style entertainment and little else. It tackles a barbed slavery subject matter in the same pressed way "Amistad" did, but lacks the vivid bit of Middle Passage horror that salvaged a small portion of Spielberg's misguided film.

Apted approaches the subject without the slightest bit of energy, entrusting the actors to breathe their own life into the script and the subject matter to stun the crowds on its own, which works if you just focus in on the acting. With fine supporting help from Albert Finney and Romola Garai (as Wilberforce's love interest and most impassioned listener), and a full-bodied performance from Gruffudd, the acting is impeccable, wallowing in that upper-class British guilt for maximum stiff-upper-lip and combustible bellow.

Running a glacial two hours in length, "Grace" wears out its welcome as it belabors the subplots to a point of irritability. Apted doesn't get caught up in the period details, he gets lost in Wilberforce's setbacks. The suspense of the voting and the twists of loyalty just aren't enough to power the drama, and as much as the filmmaker tries, "Grace" never manages to get off the ground.

Still, there's little to dislike about "Amazing Grace." History purists will find the details enchanting, period drama fanatics will adore the arm's-length posture of the piece, and the true-life tale is one worth being told. Just make sure to ingest loads of caffeine before watching.